41 results about "Quadratic formula" patented technology

The invention discloses a 6R robot inverse kinematic geometry solving method based on a screw theory and belongs to the field of robot kinematic inverse solution research. A basal coordinate system and a tool coordinate system are established, kinematic parameters of a 6R robot are determined through the basal coordinate system and the tool coordinate system, and a forward kinematic model is established; inverse solution motion of first three joints of the 6R robot is descripted in a decomposed mode, and a six-variable quadratic equation set is established; and a target position qe1 corresponding to an initial position qs1 is solved based on a screw forward kinematic model. Through the method, geometric description is combined with the screw theory, the geometrical significance is more explicit, the algebraic equation set is solved through a simplified inverse kinematic algorithm, the calculation efficiency is effectively improved, and a new inverse kinematics processing method is provided for real-time control over robot movement.

The invention discloses a method and system for estimating the historical state of distribution network based on mixed measurement. The method of the invention improves the problem of lack of SCADA measurement data in the actual distribution network by establishing a SCADA and marketing mixed measurement state estimation model. , can more accurately calculate the load and power flow distribution of the distribution network, provide more accurate and reliable basic data for theoretical line loss calculation and distribution network economic analysis, and improve the accuracy of historical state estimation. The present invention decouples the state estimation modeling from the algorithm by constructing a distribution network hybrid measurement state estimation model in the form of a quadratic equation in a Cartesian coordinate system, and can use the existing mature state estimation algorithm to solve the problem and improve the distribution network hybrid measurement state estimation model. Measure state estimation efficiency and reliability.

The invention provides a single-image space resection numerical calculation method, which comprises the following steps of: selecting three control points which are not on the same straight line from an image film, and constructing a ternary quadratic equation set according to the principle that vertex angles among corresponding light rays of three photographing light rays in an image space and an object space are equal; solving the undetermined values of the six exterior orientation elements in two steps, so that the position and attitude information of the shooting center of the shot image at the shooting moment can be determined. According to the method, the exterior orientation elements of the picture can be accurately estimated without providing any initial value, and the method is suitable for vertical photography, large-dip-angle photography and the like, and has the advantages of relatively simple and convenient calculation process, high calculation speed, accurate calculation result, stability, reliability and the like.

A method for estimating a real estate price index based on a repeat sales model. The method includes the steps of eliminating corrupt portions of data used to determine price indices; regressing a difference in a log price of a second sale minus a log price of a first sale for a property on a set of dummy variables, eliminating the observations with zero residuals for estimating the dispersion function; using a quadratic formula to model a dispersion of residual values with respect to time interval; using the quadratic formula to solve for a dispersion for each time interval starting with a minimum positive value; determining a minimum dispersion value that is a value calculated from the quadratic formula; determining a maximum dispersion value that is calculated from the quadratic formula for each time interval starting with a minimum positive value, wherein the dispersion values are prevented from decreasing with increasing time intervals; repeating the step of regressing using the inverse of the square root of fitted values from the quadratic formula as weights; identifying and selecting the time periods and associated data for estimating a price index that covers a particular time period; excluding the index values which are determined to be unreliable; and obtaining an index series for a lower geographic level by using the index series of a higher geographic level.